Beginning Monday, Metro Transit will require passengers aboard buses and trains to wear face coverings to help stem the spread of the coronavirus.

The requirement, issued by the transit agency Friday, also includes Metro Mobility and Transit Link vehicles.

Metro Transit said it will “enforce” the edict by displaying the requirement on its website, on board vehicles and at stations and bus stops.

Compliance remains voluntary. No one will be fined or denied service if they fail to wear a mask, said Metro Transit Spokesman Howie Padilla.

The Centers for Disease Control and Prevention and the Minnesota Department of Health recommend people wear a cloth face covering in public settings where physical distancing is difficult.

Metro Transit, which began encouraging face coverings in April, said the requirement will remain in place until further notice. The transit agency said it may take additional steps if there is “ongoing, widespread noncompliance,” though it didn’t elaborate on what those steps might entail.

Metro Transit said it does not have the resources to provide face coverings to passengers. The health department does not recommend masks for children under age 2 or for people who have trouble breathing or are unable to remove them without help.

Bus drivers are not required to wear masks, but rear-door boarding and barriers protecting them allow them to maintain physical distance, Metro Transit said.